The proposed research will concentrate on three problems: 1) Responsiveness of hypothalamic neurons to gustatory, visual and acoustic stimuli, to different kinds of food and to conditioned stimuli which signal different kinds of food. This study may provide data concerning the role of the hypothalamus in integration and retention of information concerning the selection of food. 2) Hypothalamic aphagia: thalamic and cortical responses as well as oral reflexes (the digastric reflex) to oral stimulation in aphagic and hypophagic cats. This study may provide data concerning the sensory and motor changes related to the oral apparatus, occurring after the lateral hypothalamic lesions, and therefore, may contribute to understanding the mechanism responsible for hypothalamic aphagia. 3) Reversal of food preference induced by brain stimulation reward. This study may help toward an understanding of the role of pleasurable sensations in food selection.